1.1 Firing systems This document applies to pulverized fuel firing systems of steam boilers and hot water generators and commences at the filling equipment for the boiler bunkers or for the pulverized fuel storage system and ends at the ash extraction plant. For multifuel firing systems using separate or combined burners, these requirements apply to the pulverized fuel firing part involved. For other fuels or firing systems used in combination, other requirements apply e.g. prEN 12952-8:2020. 1.2 Fuels These requirements cover the use of pulverized fuels (e.g. coke, anthracite, bituminous coal or hard coal, lignite or brown coal, petrol coke, oil shale and pulverized bio mass) ranging from low to high volatile matter content. 1.3 Operation Requirements for operational equipment apply for steam boilers and hot water generators with permanent supervision by properly trained persons. As firing systems using pulverized fuel may be designed either as direct-firing or as indirect-firing systems, operational requirements have to be differentiated. Annex A summarizes the operational requirements for firing systems including the pulverizing system.